Disease Proof

What are the Health Risks of Too Much vitamin D?

Vitamin D toxicity can cause nausea, poor appetite, constipation, weakness, confusion, and weight loss. Sun exposure does not result in vitamin D toxicity. Vitamin D toxicity is only a possibility from high intakes of vitamin D from supplements. The Food and Nutrition Board of the Institute of Medicine has set the recommended upper intake level to 50g (2,000 IU) for children, adults, and pregnant and lactating women. Vitamin D is one of those vitamins where the right amount is essential—not too much and not too little.

The recent Risk Assessment for Vitamin D3 sets out the reasons for raising the Toxic Upper Limit to something based on modern science rather than the present limit that appears based on junk science or myth. You can read the paper online here http://www.ajcn.org/cgi/content/full/85/1/6
The fact is, that despite people taking supplements at the official level, they remain insufficient if not deficient. See the article here. http://www.sciencedaily.com/releases/2007/02/070227105140.htm showing " 80 percent of African-American women and nearly half of white women tested at delivery had levels of vitamin D that were too low, even though more than 90 percent of them used prenatal vitamins during pregnancy,"......"92.4 percent of African-American babies and 66.1 percent of white infants were found to have insufficient vitamin D at birth."
Increasing the RDA to the actual amount of vitamin d the body actually uses daily, see Heaney http://www.ajcn.org/cgi/content/full/77/1/204 Human serum 25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol would be a step in the right direction.
Though as there may be benefits to obtaining most of your Vitamin D from direct exposure to sunlight see http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16616326Considering the potential benefits as well as adverse effects of sun exposure: can all the potential benefits be provided by oral vitamin D supplementation?
we will need to have a re-evaluation of current sun exposure policy and try to educate people to adjust their supplement intake in relation to their sunlight exposure.

phyllis -
March 2, 2010 10:33 AM

recently i have been taking 2,000 units of vitamins d and i have also experienced excessive hair loss and splitting nails. could the vitamin d be the cause?